Subversion or SVN support was added in Netbeans 6.1. It is one of my favorite and most used feature from Netbeans. For those who don't know SVN or Subversion, its a tool for software collaboration where you can easily share and checkout code differences. It is like a new generation CVS (Concurrent Versions System) and is very popular among open-source projects.
The Subversion support in Netbeans 6.1 and 6.0 is through the Versioning menu, which in 6.1 lists CVS, Subversion and Mercurial as options. CVS is working out-of-the-box without any additional work. You can select pserver, ext, local, fork and all of the access methods just work. On the other hand, Subversion and Mercurial don't work out-of-the-box and require binaries for SVN, Mercurial to be installed and Netbeans has to be told about the path where these exist.
Now why would you have to install those things separately! I always thought Netbeans did excellent bundling of all the tools. There is GlassFish, JRuby, Nice Ruby Gems... and now we also have Netbeans + MySQL + GlassFish bundle. If it was not bundled, we atleast found the good things from the Netbeans Plugins Center. Hibernate, DTrace, jMaki and other awesome things could be easily added to Netbeans through the Plugins Center, then why not SVN?? SVN is free, open-source and community driven. So bundling shouldn't have been a problem. The Netbeans FAQ on the topic doesn't give much hints, but the Guided Tour seems to be a nice place to see the feature. Even the error when SVN is not found is quite explanatory and gives good direction, but why isn't a bundle available??